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    <center>Scilab Function</center>
    <div align="right">Last update : April 1993</div>
    <p>
      <b>kpure</b> -  continuous SISO system limit feedback gain</p>
    <h3>
      <font color="blue">Calling Sequence</font>
    </h3>
    <dl>
      <dd>
        <tt>g=kpure(sys)  </tt>
      </dd>
    </dl>
    <h3>
      <font color="blue">Parameters</font>
    </h3>
    <ul>
      <li>
        <tt>
          <b>sys</b>
        </tt>: SISO linear system (syslin)</li>
      <li>
        <tt>
          <b>g</b>
        </tt>: constant</li>
    </ul>
    <h3>
      <font color="blue">Description</font>
    </h3>
    <p>
      <tt>
        <b>kpure(sys)</b>
      </tt> computes the gains <tt>
        <b>g</b>
      </tt> such that the system
    <tt>
        <b>sys</b>
      </tt> feedback by g (<tt>
        <b>sys/.g</b>
      </tt>) has  poles on imaginary axis.</p>
    <h3>
      <font color="blue">Examples</font>
    </h3>
    <pre>

s=poly(0,'s');
h=syslin('c',(s-1)/(1+5*s+s^2+s^3))
xbasc();evans(h)
g=kpure(h)
hf=h/.g(1)
roots(denom(hf))
 
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    <h3>
      <font color="blue">See Also</font>
    </h3>
    <p>
      <a href="../graphics/evans.htm">
        <tt>
          <b>evans</b>
        </tt>
      </a>,&nbsp;&nbsp;<a href="krac2.htm">
        <tt>
          <b>krac2</b>
        </tt>
      </a>,&nbsp;&nbsp;</p>
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